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LPC1347 send large data to Endpoint in a single transaction

Question asked by Yongyong Li on Aug 1, 2017
Latest reply on Aug 2, 2017 by Carlos_Mendoza

Hi all,


I am using a LPC1347 usbd_rom_composite example codes(lpcopen_2_05_keil_iar_nxp_lpcxpresso_1347). 

I am trying to send data with size of over 10240 bytes to endpoint 0x82(device to host). And these 10240 bytes of data must be in one transfer. Data rate is not important.


My device is Full Speed and the endpoint 2's wMaxPacketSize is 0x40(64).



My problem is, when I was calling the USBD_API->hw->WriteEP() and set the data length larger than 64, my device sent unpredictable data length(not the one I set).


I have also tried to devide data into 160 chunks(every chunk is 64bytes)  and call the VCOM_Write() 160 times, but it gives me seperate transactions with 64bytes each. What I need is a single transfer with 10240 bytes of data. Is there anyway to achieve it?


Thank you in advance!


Li Yong